1. Field of the Invention
The invention relates to a device for solidifying a layer of a liquid that solidifies upon cooling, such as agar contained in a row of petri-dishes or the like. The invention particularly relates to a device which may be combined with existing apparatuses for the preparation of agar plates in petri-dishes.
2. Description of the Prior Art
Modern apparatuses enable the manufacture of agar plates in petri-dishes in large numbers, so that a laboratory worker may quickly have large numbers thereof at his disposal for testing large series of microbiological activities and other purposes. Dishes are filled automatically with a predetermined amount of liquid agar. The dishes are supplied to a stacker until a predetermined height is reached. Those stacks may then be taken from the apparatus for further use. In this automatic process, when the dishes leave the supplier, the agar contained therein is still in a liquid state. Thus, the dishes are stacked while the agar is liquid, so that the agar solidifies in stacked condition. Since the dishes are steadily in motion during stacking, i.e., during solidifying, a rippled surface is caused. It is evident that this rippled surfface is not desired, since it influences in general, inadmissibly disadvantageously the accuracy of biological activity measurements to be made afterwards.
The above mentioned disadvantage could be avoided by placing, between the supplier and the stacker, a cooling zone, in order that the petri dishes reach the stacker when the agar is solidified. To achieve such purpose, a relatively long cooling zone would be necessary, resulting in much occupied room.